Contaminated surfaces are an important potential source for transmission of Clostridium difficile, and some interventions to improve environmental cleaning have been associated with reductions in CDI. However, few interventions have included monitoring to confirm the efficacy of spore eradication and there is uncertainty regarding optimal strategies for environmental disinfection. The goal of this proposal is to develop evidence-based environmental disinfection strategies and test their effectiveness in reducing rates of healthcare-associated CDI. Our specific objectives are: Objective 1. Determine if an intervention that includes ongoing monitoring and feedback will improve environmental disinfection by housekeeping staff. Our working hypothesis is that an intervention including active participation by housekeeping staff and ongoing monitoring and feedback (i.e., enhanced cleaning) will result in sustained improvement in eradication of spores. We will perform a before and after trial of a fluorescent marker method to provide monitoring and feedback. The primary outcome measure will be effectiveness of CDI room disinfection. Incidence of healthcare-associated CDI will be a secondary outcome measure. Objective 2. Determine if adjunctive use of a mobile, automated UV-C radiation device will further enhance environmental disinfection. Our working hypothesis is that adjunctive use of an automated UV-C device will result in further improvement in eradication of spores and reduction of CDI incidence in comparison to enhanced cleaning. To accomplish this objective, we will perform a 2-year randomized trial of 12 wards at the Cleveland VA Medical Center using a cross-over design. The primary outcome measure will be incidence of healthcare-associated CDI. Objective 3. Determine if an enhanced cleaning intervention will reduce rates of healthcare-associated CDI in multiple VA hospitals. Our working hypothesis is that an enhanced cleaning intervention that includes active participation by housekeeping staff and ongoing monitoring and feedback using the fluorescent marker method will reduce rates of healthcare-associated CDI. To accomplish this objective, we will perform a 1-year randomized trial of multiple VA hospitals to compare standard cleaning (i.e., monitoring of cleaning through observation only) versus enhanced cleaning (i.e., including monitoring and feedback using the fluorescent marker method). The primary outcome measure will be incidence of healthcare-associated CDI. .